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Any time current flows through a conductor an electromagnetic field is formed around the length of that conductor. The direction of current flow determines the polarity of this magnetic field.
Wiki User
∙ 16y ago
Wiki User
∙ 10y agoShort Answer:
The alignment of a compass results from the basic laws of attraction and repulsion between the poles of magnets. The North pole of the compass will be attracted toward the South pole of a magnetic object and, vice versa, the South compass pole will be attracted to the object's North magnetic pole. The resulting orientation of the compass is then said to be in alignment with the magnetic field of the magnetic object.
Longer Answer:
A compass is a small magnet and it is useful because it aligns with the magnetic field of the Earth, approximately north and south. The North pole of any magnet is attracted to the South pole of any other magnet and, conversely, the South of any magnet is attracted to the North of any other magnet. Likewise, the North pole of any magnet is repelled by the North pole of any other magnet and the South poles repel in an identical fashion.
If we accept the basic laws of attraction and repulsion of magnetic poles, then the alignment of a compass (or any other magnet) is a result of the forces on the North and South poles of the magnet, being such at to orient the North pole of the compass closer to the South pole of the other magnetic object and further from the North pole of the other magnetic object. At the same time, the South pole of the compass is pulled towards the North pole and away from the South pole of the magnetic object creating the field. The resulting alignment is actually the definition of the direction of the magnetic field of the magnetic object.
The alignment of a compass is therefore a consequence of the basic laws of attraction and repulsion between the poles of magnets.
While the Earth has its own magnetic field and the source of that field is deep in the Earth's core, the characteristic of a compass aligning with the Earth's magnetic field is exactly the same characteristic as a compass aligning with the magnetic field of any magnet. Of course, a strong magnetic field creates a stronger twisting force on a compass needle and so the alignment of a compass needle indicates the combined forces of any nearby magnets and the relatively small magnetic field of the Earth.
This all has to be explained in a self consistent fashion. A magnet will align with a magnetic field and that property is used to define both the magnetic field in strength and direction. The explanation of why a magnet aligns in a field can quickly become circular, i.e. if you define the direction of a magnetic according the to alignment of a magnet, then it is useless to say that the magnet aligns because it wants to be in the direction of the magnetic field.
To explain further why a magnet aligns with a magnetic field, one must start by delineating the basic observations and experimental facts which one takes to be true without explanation. (One need never take anything to be true without explanation, but digging deeper is really the answer to questions about the origins of the fundamental forces of nature and thus an answer more complex than this one.)
Caveat:
Here is a list of several caveats being acknowledged which would be addressed in a longer and more complete explanation.
1. Magnetic fields can be created by electricity as well as a permanent magnet but field of an electric current has no North or South pole even though a compass will respond with an orientation that is aligned with the local direction of the field due to the electric current.
2. Magnets are not monolithic objects, but are actually made up of many atoms, each having the properties of a small magnet, so actually the magnetic field of an object is caused by these many small objects and the forces a maggot experiences in a field are the cumulative forces on all the atoms as a result of their magnetic characteristics.
3. Magnets are attracted (or repelled) by nonmagnetic objects, but this is a consequence of the magnet properties of the constituent atoms of the nonmagnetic which are altered by the presence of the field of the magnetic object.
A course on the subject of electricity and magnetism would cover all these topics and give the mathematics needed to produce a completely consistent description.
Wiki User
∙ 12y agoThe answer is in the question. Current in a conductor causes a magnetic field.
A compass uses a magnetised needle to align with the earths magnetic field.
Like poles repel, opposite poles attract. The magnetic needle in a compass will act like any other magnet and will be attracted to another magnet.
Wiki User
∙ 16y agoWhen you pass current through a conductor it creates a magnetic field around the conductor.
Wiki User
∙ 10y agoAny moving current produces a magnetic field,
which is what affects the compass needle.
Wiki User
∙ 12y agothe compass will line up with the magnetic field produced by the current
Wiki User
∙ 8y agoIt doesn't - unless the wire is carrying a current.
Wiki User
∙ 8y agoThat will happen if there is a current through the wire. The wire produces a magnetic field, and the compass reacts to that.
Wiki User
∙ 8y agoA flowing current is surrounded by magnetic fields. The compass needle reacts to those, since that's what a (magnetic) compass does.
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Can you use a compass to detect the currents in wires in the walls near light switches in your home?
Yes, the needle would point perpendicular to the wire, and parallels to the magnetic lines of the wire. Another answer The above answer would be correct IF you were dealing with a DC circuit AND there was a load on the circuit, but house wiring uses Alternating Current, and the compass needle would attempt to reverse directions at the rate of 60 cycles per second. Effectively, the needle would simply act strange when it's near house wiring, IF there is a current load on the wire. ++ To add to that, use a proper cable-locator, not a compass.
What would a compess point to if you were at the north pole?
If you are at the North pole, the north point of the magnetic needle in the compass will tilt a little downwards, and the south pole of the compass needle will tilt upwards. If you hold the compass in a direction vertically perpendicular to the surface of the Earth, the needle will align itself like the earth's magnetic field, as if it were a huge bar magnet, the north part of the needle facing upwards.
Where should a timer be installed - at the electrical outlet or the end of a power cord?
The outlet would be the more often recommended place for it.An electrical timer can be placed anywhere within the circuit. Usually the timer would be placed at the front end of the circuit.
If you were in Uruguay and looked at your compass which way would the needle be pointing?
It depends which direction you're facing, it has nothing to do with where on the planet you are.WRONG ANSWER! Regardless of WHERE you are, or WHICH way you are looking, the compass needle will point to the NORTH. Not to the NORTH POLE mind you, but to the MAGNETIC NORTH, which is a little bit off from the TRUE NORTH and also MOVES a little bit every year. This is called VARIATION and depending on where you are, the TRUE NORTH may be to the right or to the left of where the compass needle points. Your reading will also be a little bit off to one side or the other, depending on which direction the needle is pointing (hey, nobody's perfect), but this is predictable and can be measured when the compass is calibrated (a process called swinging the compass). This is called COMPASS DEVIATION (don't think deviate now...) Another change may happen if you are going from West to East or viceversa AND you are accelerating or deccelerating, in which case the needle will lag. Last but not least, if you have any kind of magnetic interference near the compass, like a screwdriver with a magnetic tip, oh well then... the needle may be pointing God knows where.Northnorth because that's what way compasses point.
Does the Aurora borealis influence compass needles?
Scientists observed disruption of a the magnetic needle of a compass by the electromagnetic interference by Aurora Borealis which reflected perfect direction that coincided with the view of the phenomena. It was concluded this would only happen if electric currents were setting from south to north in the earth under the needle, or from north to south in space above it.
Can you use a compass to detect the currents in wires in the walls near light switches in your home?
Yes, the needle would point perpendicular to the wire, and parallels to the magnetic lines of the wire. Another answer The above answer would be correct IF you were dealing with a DC circuit AND there was a load on the circuit, but house wiring uses Alternating Current, and the compass needle would attempt to reverse directions at the rate of 60 cycles per second. Effectively, the needle would simply act strange when it's near house wiring, IF there is a current load on the wire. ++ To add to that, use a proper cable-locator, not a compass.
When a compass is placed near a conductor where current flows its needle would deflect what does this indicate?
This proves that a magnetic field is developed around the conductor wen current flows through it...
What metal material would be best for a needle of a compass?
Iron or steel
Which test can best detect the presence of electrical current a the needle of a compass b the bulb in an electric circuit blows c the plug of an iron is placed in the socket?
Here are some possible answers: a) If you hold a compass close to a wire you may see the needle move. How much it moves depends on the strength of the current flowing in the wire. If the needle doesn't move then there may be three explanations: 1) No direct current was flowing in the wire OR 2) a direct current was flowing but it was too weak to make the compass needle move OR 3) there might have been a current but it was an alternating current changing so fast that the needle did not seem to move. b) If the bulb in an electric circuit was lit but then blows, it may mean one of two things 1) the current was switched off so the bulb went out OR 2) the bulb just died, in which case any current that was flowing in the bulb's circuit would stop. c) when the plug of an iron is placed into a socket, if it warms up then a current must be flowing from the socket to the iron. But before the iron was plugged-in, no current was flowing. Now you work out which of those answers to this question is the right one!
If you made another compass with the same materials would the needle point be in the same direction?
the needle points in the direction the magnetic fields wish. The gravity pulls the compass nearer and nearer the magnetic fields.
What would indicate an magnetic field?
You can detect it by watching a compass needle, if that's what you mean.
What do you need to make a floating compass?
You would need a piece of cork or other soft floating material, perhaps polystyrene, also a needle and a magnet. stroke the needle with the magnet a few times in the same direction and them insert the needle into the floater so that it is horizontal when the floater is placed in water, place floater into a container of water, the needle will point toward the magnetic north.
What would a compess point to if you were at the north pole?
If you are at the North pole, the north point of the magnetic needle in the compass will tilt a little downwards, and the south pole of the compass needle will tilt upwards. If you hold the compass in a direction vertically perpendicular to the surface of the Earth, the needle will align itself like the earth's magnetic field, as if it were a huge bar magnet, the north part of the needle facing upwards.
What tool would you use to detect magnetic effects?
A magnetic needle meter, or a simple compass.
What is the function of liquid chamber in a magnetic compass?
The liquid is there to dampen the movement of the needle. Without the liquid, the needle would spin and jiggle about rapidly. Hence the need to slow the movement down - it makes the compass easier to use.
In the southern hemisphere the north pole of a compass needle?
The north pole of a compass needle would still point point towards the north. More precisely, towards the Earth's magnetic south pole, which is close to the geographic north pole.
Where should a timer be installed - at the electrical outlet or the end of a power cord?
The outlet would be the more often recommended place for it.An electrical timer can be placed anywhere within the circuit. Usually the timer would be placed at the front end of the circuit.
